Rotary compressor or pump



April 3, 1934- H. OGILVIE v 1,953,253

ROTARY COMPRESSOR OR PUMP Filed March 4, 1952 2 Sheets-Sheet 1 P fig 5 17 Gaza/15 pn'fili 3 39M H. OGHLVIE 199539253 ROTARY COMPRESSOR OR PUMP Filed. March 4, 1952 2 Sheets-Sheet 2' I Patented 1934 Henry Ogilvie, London, England Application March 4, 1932, Serial No. 596,838

' In Great Britain March 4, 1931 r v i 1 Claim.

This invention relates to rotary compressors for air or other gases of the type having radial vanes sliding relatively in a rotor arranged eccentrically to the barrel, it being understood that the term air hereinafter used in the specification and claim includes other gases. Attempts have been made to lubricate and to seal the vanes by means of oil, the oil discharged with the air or gas'being separated therefrom and iii returned to the compressor or pump.

When intended for the compression of air up to farly high pressures, for instance, about .100 lbs. per square inch or more, it is usual to provide the compressor with a cooling jacket and also to it compound several compressors, except in the case of compressors of small capacity.

The object of the invention is to enable efl'ective lubrication, sealing and-cooling to be obtained in a very simple manner which reduces to the necessity for .the complication of cooling Jackets on the compressor and also forcompounding, even tor the compression of air up to about 100 lbs. per square inch or more, in the case oi compressors oi larger capacity, or higher at speeds, than. have hitherto been possible.

According to the invention, a compressor of the hnown type comprising a cylindrical casing,

for convenience hereinafter termed a barrel", he an air inlet and a compressed air outlet, to and a rotor eccentrically mounted in said barrel to to therewith an air-chamber, the rotor having radial sliding vanes, has orifices in the end plates oi the barrel through which cooling oil is injected, in the form ofv jets or as fine spray, ditii rectly into the air chamber to be mixed intimate- 1:7 with the air therein and thereafter tostrike the forward surface of each vane and to be thrown by centrifugal action against the barrel where it makes an efiective seal against leakage to of air or gas past the vanes, means being provided for not only separating the oil from the air discharged, but for cooling the separated 011 beiore its return to the compressor. If desired, the mixture of compressed air and oil may be cooled to either partly or wholly before separation. Lubrication oi the suction side of the compressor is insured by .a small but sumcient quantity of oil being carried past the rotor seal by each revolving blade. H to In the accompanying drawings:

Figures 1 and 2 are sectional elevations of one form of compressor providedwith cooling and sealing means according to the invention, the sections being taken respectively on the line I---I 66 and 11-11 of each figure. p

- being. separated.

Figure 3 is a detail sectional view on a larger scale showing one of the injection holes and the screen orstrainer.

Figures 4 and 5 are sectional views. the sections being taken respectively on the line IVIV and V---V of each figure, showing a second form of atomizer for the 011.

Figure 6 is a diagrammatic lay-out pressor and auxiliary plant.

In the example illustrated, the compressor comprises a barrel. 1. having an air inlet 2 and compressed air or gas outlet 3. A row! 4. eccentrically mounted in the barrel 1 on a shaft 4' is provided with radially sliding blades or vanes 5 which beer at their outer edges on. the inner wall of the barrel 1 and at the side edges against end plates 6. The barrel 1 has hollow end covers of the com- -7 and is which communicate with each other by holes 9, recesses 9" inthe central part of the rotor, and the slots 10 for the blades. The end covers form oilvreservoirs 30, 31, oil being admitted to them through. pipes 11 and 12. 7 Each and plate 6 is provided with an orifice or a series of injection orifices 13 which may be filled with helically grooved plugs 14 (Figure 3), so so that oil from the reservoirs enters the air chamber oi the compressor in a whirling and atomized form to cool the air and to settle as spray on the forward sides of the blades or vanes to be thrown by centrifugal action towards the cylindrical surface of the el 1 and 'seal the blades against leakage of air past them. 1 Each seriesof orifices may be covered by it screen or strainer 15 carried by a plate 16 fixed by screws 1'7 to the end plate, as'shown more clearly in Figure- 3.

It will be appreciated that the oil discharged with the compressed air at 3' may be separated in a suitable separator and be passed through a cooler before being returned to the compressor, as is well known practice in the'art. The separator may be used to cool the oil and the cooled oil can then be returned to thecompressor; or the air and oil maybe partly or wholly cooled before As shown in Figure 6, the compressor, designated, generally by the numeral 18 is driven by a direct coupled electric motor 19. The compressed airand the intermixed cooling oil pass out of the compressor through a pipe 20 to any 1 suitable separator 21. The compressed air, free from oiL'can be led from the separator through a service pipe 22 which maybe controlled by a valve 23. The separated oil then through a pipe 24 to a cooler 26 of any well known type.

- The cooler is provided with the usual inlet and.-

:stantially radial ports, in the rotor or in outlet connections 26. 27 for the cooling water. The cooled oil is ledby a pipe-28 through a strainer 29 from whence it passes back to the oil reservoirs 30, 31 in the compressor, through pipe 32 and branches 11 and 12.

Such a circulatory system for the oil ensures that the oil is maintained at a substantial pressure to ensure its injection into the air space of the compressor.

There is a tendency for air carried into the reservoirs 30, 31 by the oil to collect at the top of the reservoirs. There is a tendency tor this air to collect to such an extent that it prevents the oil level reaching the height of the bearinas for the shaft 4'. This may be avoided by providing a pipe 33 which can vent this-air to the barrel. The pipe may be screwed into a plate 16 and have its lower end in communication with an orifice 13 through a channel 34. one or both reservoirs may be provided with a pipe 33.

The orifice or orifices 13 may be directed at various angles, if desired, to ensure that the whole v of each blade is sprayed with oil and the oil is sprayed through-out the air chamber. The holes 13 being arranged in series ensure that oil is injected continually into the air or as during the passage oi. the blades past them.

As the oil can pass betweenthe endcovers or reservoirs and the slots in the rotor, the rotor is also cooled.

Introduction of cool oil into the compressor reduces the power required for compression and keeps the parts cool enough to maintain the viacosity of the oil to-ensure adequate sealing.-

The injection oithe cooling oil into the com pression space the end plates of the har-v rel, .is moreeihcient than injection through sub-' cylindrical-wall of barrel. as has been aux-r tested for lubricatin l-oil. 011 injected from ends of the bar'r'elisbetter mew mix with the air under comprassion; and so insure efllcient. cooling. The edges of the blades or vanes in 1 contact with the cylindrical wall 01' the barrel are rounded oil at a radius smaller than that of the of each vane as the vane passes over the port.

This connection may cause ablow back and consequently a slight loss 01 pressure on the pressure side of the vane.

It will be appreciated that in the present invention the orifices 13 may be of considerable size passage of a vane 5 over them.

. before such a blow back could occur during the Further the connection .0! thetwo oil reservoirs I and 31 by the 3; recesses Qihildfslots 10 ensures the presence of cooling oil, under pressure, behind the-vanes 5, so that the vanes may be maintained against the cylindrical wall of the barrel. oil is kept under pressure throughout its circuit, so that it may be injected into the air space.

If desired, the oil may be injected into the compression space through an atomizer such as is shown in Figures 4 and 5. Each injection orifice 13 is formed in a plug 35, preferably of hardened toolsteel. The'plug 35 is screwed into the end It will be appreciated thatthe cooling plates '6 and is provided at its outer endwi thjtwo tangential slots 36 which. enter a conical portion 37 of the orifice 13. A cover 38 is ,screwed onto the plug and is provided with a number ofholes 39 which, by meansoi a-circumierential. recess 40 inthe cover 38, are in communicationwith the tangential slots, 36. ,Oil in ,the reservoir passes through the holes 3 9., and the tangential slots .36 cause it to intothe conical recess with a whirling motion, so that ltbe comes atomized, ..v "I A" rotary compressor-tor air, comprising a cylindrical barrel having end plates an inlet and a' compressed air out1et. -a rotor eccentri'cally t new hflmw rzy m; the a: th rei to Iorwardside each vane and to be torcedby centriiugalaction ls s ie in r h ines; g t barrel -aeal the vanes ieakaseot'airp t th m-mean tor supplyinldkunder Dream to "M1 partments, and t0 thccom pressed air outlet oi said cash: for: S p rating .oil

from the compressed.alr d ch rsedr-thereirom,

substantially as and .201 the purposes hereinbeiore set forth. 

